The short answer is yes. The long answer is a lot depends on tides and currents and the structural integrity of the boat. I am sure so ex-dolphins will be by shortly to give you a much better explanation.
I imagined rocking it back and forth like you do a car stuck in the snow. I imagine the gearshift lever is a little different, though.
I've been waiting for a submarine thread, because I've become curious these past two weeks....I am wondering what the effect would be on a submerged sub in the path of a tsunami; I understand they can travel at hundreds of miles per hour underwater until they approach a land mass.
High tide may have helped float the boat out!
How about blowing the tanks and floating off ? < disclaimer>This coming from a land-lubber...< /disc>